My experience.
I drove from Memphis, TN to Yellowstone National Park, a distance of over 3,000 miles. When I got home I had an absolutely flat tire on an inside dually.
I think I know when I picked up the nail in that tire. I visited my sister in Calhan, CO. My GPSr took me to a privately owned barn on a farm. I think I picked up the nail turning around to come back out. If so, that means my tire started leaking air about 1,000 miles from home. How long it took to leak down, I don't know, but it was a 2 day drive from there home, so I drove 2 days on a flat, at most.
I had the tire patched, and drove on both it and the original dually mate for another 2 years. After that time, the tires were 7 years old, so I replaced all 7 tires (I also replaced the spare).
I know, I should have been checking my tire pressure every day, but didn't. I checked it at home before leaving, and at Yellowstone before starting back.
I now have a TPMS system.